1. Field of the Invention
The present invention refers to an engine assembly that includes an internal combustion engine and a steam engine connected to a driving assembly, for instance, by a common driving axle, and further includes a heat exchanged by which heat losses, from exhaust gases or cooling water, or both, from the internal combustion engine are utilized for generating steam to the steam engine.
2. Description of the Related Art
It is conventional to utilize combustion gases from an internal combustion engine in order to improve its efficiency, an internal combustion engine referring here to otto-cycle and diesel engines. The most common device presently in use is an exhaust driven turbo turbine driving a turbo compressor for supercharging the intake combustion air, which improves the performance of the engine at high shaft speeds. In large ships it is also customary to use steam turbines in order to utilize the heat from the exhaust gases of diesel engines. It has also been proposed to use exhaust gas heat from an internal combustion engine in a Rankine cycle process for the purpose of increasing engine efficiency. However, in conventional steam technology, the steam engine with its auxiliary system is too bulky and heavy. Therefore, these conventional systems have not been considered as a realistic alternative for vehicles in which weight and space demands are of great importance.
From a thermodynamic point of view, a piston steam engine could be a possible solution for utilizing the heat losses of an internal combustion engine. However, in such a case, the weight and space demands of the system must be considerably reduced compared to that provided by present steam technology.